Carburetor



Feb. 28, 1939. A A DlCKE 2,149,116

CARBURETOR Filed Oct. 17, 1933 2 SheetS-Sheei 1 INVENTOR Auf/v A. /drfFeb; za, 1939. `A. A. DICKE 2,149,116

' CARBURETOR I Filed oct. 17, 193s 2 shams-sheet 2 INVENTOR Auf/VA /KfATTORNEY Patented Feb. 28, 19,39

UNITED STATES PATENT OFFICE 7 Claims.

My invention relates to carburetors for internal combustion engines andparticularly to carburetors adapted for use on motors or engines whichmay be tilted or moved about a horizontal axis either when in use orwhen inactive.

Outboard motors, airplane engines, and motor car engines are typical ofthose to which my invention is particularly applicable. .For instance,outboard motors are commonly constructed so as to tilt about a pivot topermit the propeller to be raised over obstacles in the Water or toenable the motor to be used in shallow water. motor is also tilted to aninclined position when it is not in use, particularly when anchored inshallow Water. The carburetors now used vare generally constructed .withav iioat chamber in which a supply of fuel is maintained during use, butwhen the motor is tilted, the carburetor is moved therewith and thelevel of the fuel in the iioat chamber with respect to the spray nozzleor jet from which the fuel is discharged into the mixing device isaltered, so that either too much or too little gasoline is fed to theengine. For this reason, the operation of the carburetor and motorbecomes irregular. Furthermore, even though the motor is not operatedwhen it is tilted to its inactive position, gasoline leaks out of theoat chamber about the cover, or drains through the spray nozzle andflows into the bottom of the boat. If the valve between'the gasolinetank and the carburetor is not closed, the whole tankful of gasoline maydrain out into the boat;- This not only wastes gasoline but makes theboat untidy and oily producing a dangerous and very undesirablecondition. Even when the motor is not tilted so far as to cause thegasoline to be spilled out of the oat chamber. the level of the liquidin the float chamber may be considerably altered or the position of theoat with respect to the liquid in the chamber may be changed when themotor and carburetor are tilted, so that the operation of the enginebecomes irregular. In addition, in motor vehicles, upon quickacceleration or deceleration, the gasoline in the carburetor tends tocollect at one side of the float chamber and assume an angle oblique toits normal position, resulting in the same effect as produced by atilted carburetor.

In order to overcome the diiculties presented by carburetorconstructions of the prior art, I have devised a novel type ofcarburetor including a oat chamber, float, and discharge nozzle or-jet,in which the elements are maintained in substantially the same relativepositions even though the engine and carburetor are tilted The.

through avery large angle. In constructions embodying my invention, thelevel of the liquid in the float chamber and the position of the oatwhich controls the flow of liquid into the float chamber remain the samewith respect to the horizontal axis about which the carburetor is tiltedeven when the engine is inclined atA an angle of 45 to 60 or more fromnormal. The position of the spray nozzle with respect to the liquidlevel is also maintained substantially the 10 same throughout tilting ofthe motor and carburetor.

One of the objects of my invention is to insure uniform operation of acarburetor in various angular positions.

Another object of my invention is to provide a carburetor'having a floatchamber and a iioat which maintain the same relative positions withrespect to a horizontal axis when the carburetor is tilted through alarge angle, viz. the float chamber and float being so formed that whenthe carburetor as a whole is oscillated about a transverse axis theplane of the liquid level therein will always pass through a singletransverse line, assuming that no liquid isadded or removed therefrom.

A further object of my invention is to provide a carburetor in which therelative positions of the liquid level in the float chamber and of thedischarge outlet through which the liquid is passed into the mixingdevice remain substantially the same when the carburetor is tilted, orupon sudden acceleration or deceleration thereof.

A further object of my invention is to'provide a carburetor having aioat chamber with a float therein which is formed with walls spaced fromthe walls of the float chamber'an equal distance on all sides thereofthroughout that .portion of the float and chamber which are in contactwith the fuel in various positions of the carburetor. 40

These and other objects and features of my invention will appear fromthe 'following description thereof in which reference is made to theaccompanying figures of lthe drawings illustrating a typical embodimentof my invention.

In the drawings:

Fig. l is an illustration of an outboard motor having a carburetorthereon embodying my invention.

Fig. 2 is' a vertical sectional view of the carburetor illustrated inFig. l taken on the line 2-2 of Fig. 3. l

Fig. 3 is a vemrtical sectional view of the form of carburetorillustrated in Figs. l` and 2, taken on the line 3 3 of Fig. 2, thefloat being shown in full.

Fig. 4 is an elevation of the carburetor looking from right to left ofFig. 3.

In the drawings, I have illustrated a conventional outboard motorcomprising an engine 2 having a drive shaft housing 4, and a propeller6. In motors of this character, it is usual to mount the engine, driveshaft and propeller on a bracket 8 secured to the boat on which theengine is to be used as by clamp screws 8a. In order that the propellermay be raised out of the water into an inactive position and to permitthe motor to be tilted so as to raise the propellerv over obstructionsin the water or when the boat is used in shallow water, the motor andassociated parts are pivotally secured to the bracket 8 for movementabout a horizontal axis I0. The carburetor I2 is secured in fixedposition relative to the engine 2 and the gasoline supply tank 2a sothat when the motor is tilted the carburetor moves with the engine andtank about the axis I0.

As shown in the drawings, the carburetor is provided with a ioat chamberI4 to which fuel, such as gasoline, is supplied through an inlet passageI6 controlled by the valve I8. Movement of the valve is effected in theusual manner by means of a float 20 through the arm 22, pivotallymounted at 24 in the upper portion of the float chamber, so that fuel ismaintained at a substantially constant level in the oat chamber at alltimes. The density of the float 20 is so selected that when it issubmerged to its central axis it has just suicient buoyancy to close thevalve I8 and thus to maintain the liquid level as shown. Gasoline issupplied to passage I6 through a tube IGa connected to tank 2a. Gasolineor other fuel is drawn from the oat chamber through the conduit 26 tothe spray nome 28 or other discharge device for mixing fuel with air toform an explosive mixture for the engine.

The oat chamber I4 is formed so as to permit the carburetor to be tiltedthrough a relatively large angle, say 45 or more, without permitting thegasoline to spill out of the carburetor. While the size and shape of theoat chamber may be varied considerably in different constructions oruses of the carburetor, I prefer to employ a float chamber the innerwalls of which are inthe form of a figure of revolution with respect toan axis 30 coinciding with the v'normal liquid level maintained in thechamber. As illustrated, the float chamber is substantially cylindricalin form throughout that portion thereof in which the liquid ismaintained. Tilting of the carburetor about Vthe axis-30 therefore doesnot alter the position of the liquid with respect to the axis 2li. Sincethe axis 30 of the float chamber is parallel to the axis I0 about whichthe motoris movable, tilting of the motor is the equivalent in itseffect upon the liquid in the float chamber to tilting of the carburetoralone about the axis 30. For thisreason, the level of the liquidmaintained in the float chamber remains the same when the 4motor anddrive shaft are either in the full line position or the dotted lineposition shown in ris. 1.

In order that the supply of fuel ,from the supply tank 2a of the engineto the iioat chamber may not be altered by movement of the float withrespect to the liquid in the chamber as a result of tilting the motor,the float 2B is so formed that the amount of liquid displaced is thesame in' any position which the float may assume relative to the fuellevel as a result of tilting the motor. This result may be attained byforming the float with walls spaced uniformly from the walls of thefloat chamber throughout that portion of the float which passes into andout of contact with the liquid upon rotation of the carburetor through alarge angle, say 45, or more. As shown, the float is in the form of acylindrical member of such specific gravity that it is immersed in theliquid to a suii'cient extent to maintain the axis of the floatsubstantially in alignment with the axis of the iioat chamber and alsoin alignment with the liquid level maintained in the float chamber. Withthis construction, it will be apparent that tilting of the motor fromthe full line to the dotted line position shown in Fig. 1 does not alterin any Way the relative positions of the float, the iioat chamber, andthe liquid Within the chamber. This will be readily apparent if it isassumed that `the carburetor shown in Fig. 2 is tilted to a position inwhich the liquid level is vrepresented by the line XY. That portion ofthe float ywhich is submerged in tilting the carburetor to thelattervposition is equal in volume to that portion which is exposed bysuch tilting (which is accomplished in the form shown by cylindricalshape of the float, although various other shapes of float wouldaccomplish the same result). Furthermore, the space between the fioatand the walls of the float chamber which is lled by liquidwhen thecarburetor is tilted, is equal in volume to the space which is vacatedby such tilting (due to the cylindrical form of the walls in the formshown, although various other forms of chamber would accomplish thesame' result, the shape thereof vtaking into consideration the shape ofthe oat to be used). As a consequence, according to the presentinvention, there'isv a certain transverse horizontal line (30 in the'-`form shown) which lies in the surface of the liquid in all positions oftilting of the carburetor.. The vaporizing nozzle 28 is preferablylocated just above this line which may be referred to as the liquidlevel line. This insures uniform operation of the carburetor at alltimes and in various angular positions of the motor. The angle of thesurface of the liquid relative to the chamber may be varied not only bytilting of the motor but also by the effects of acceleration anddeceleration of the boat or other vehicle in which the carburetor isused. For example, a rapid deceleration, as by the application ofbrakes, will cause the liquid to move forward in the chamber and assumea level approaching the plane XY, i. e., a plane at right angles to theresultant of the action of the force of gravity and the deceleratingforce. However, in view of the construction shown and described, thischange in position of the liquid does not cause the float to drop andcause additional fluid to enter so that when the braking stops4 and theliquid surface returns to horizontal its height is neither higher norlower than normal.

If the float were positioned at either side of the center of the oatchamber, tilting of the carburetor would cause the float' to be moved upor down with respect to the inlet' arm 22 so that the valve I8 would beraised or lowered and the tupply of liquid to the chamber and the carbu-.due to the rise and fall of the liquid as it passes into and out of theoat chamber may therefore take place as required without danger ofdisplacing the float materially from the center o the oat chamber.

Y In order that movement of the float within the float chamber may takeplace readily at all times and When the carburetor is tilted to eitherof its extreme positions, I prefer to employ means serving to guide theiioat in its movement within the chamber and which at the same timepresent the least resistance to the movement of the float. As shown inFig. 2 when the carburetor is in the positionA Shown in full lines,corresponding to the normal vertical position of the engine, the floatwill move up and down with changes in the level of the liquid along aline inclined at an angle of say 30 degrees to the left from vertical.However, when the carburetor is tilted so that the liquid takes up theposition indicated .by the line X-Y, as when the motor is tilted to thedotted line position of Fig. l, the movement of the float will be alonga line inclined at the same angle to the right from vertical. Movementof the float as described is in substantially a straight line bisectingthe angle between the planes assumed by the surface of the liquid in thechamber when the carburetor is moved to each of its extreme positions.Operation of the lloat is therefore the same in both extreme positionsof the engine, and is at no time along a line at such an angle relativeto the surface of the liquid that amr material resistanc'e is oifered tothe movement of the float.

In order to permit easy assembly of the parts, the carburetor isprovided with a cover 42 for the float chamber which may be secured inplace by any suitable means and a stud 44 on the 'top of the oat isjournalled in an opening or recess 46 in the cover. The float may beeasily introduced into the iloat chamber when the cover is removed andpositioning of the brackets 34 on the bottom of the float in engagementwith the projection 36 in the bottom of fthe float chamber may bereadily effected and thereupon the valve lil, and rock- -ing lever 2tare put'in position, thereupon the pivot screw 22a is put in place.

The carburetor may be provided with the usual choke 43 and throttle 5tand adjustment of the flow of liquid through the outlet lll in the spraynozzle 2li may be regulated by adjustment ci the needle valve 52 as inthe usual carburetor construction. The carburetor is attached to theengine in any desired way as by clamping the collar 38a to the engineintake passage.

While I have illustrated and described a preferred form of carburetor,embodying my invention, the float chamber and float may take variousforms other than that shown herein, provided tilting of the carburetordoes not alter the relative positions of the float, the' liquid level inthe float chamber, relative to the liquid level line and the outletopening through which liquid is discharged from the'spray nozzle. Thus,for example, I may employ a float chamber and float which are in theform of a cylinder with a vertical axis provided the walls of the floatare spaced uniformly from the walls of the float chamber and the amountof the float extending above and below the normal liquid level aresufficiently extended to permit tilting of the carburetor through arelatively large angle Without covering o r exposing either the upper orlower end thereof. With this construction, tilting of the carburetordoes not alter the position of ,either the lloat or the liquid levelwithin the float chamber for the reason that the volume of the liquiddisplaced on one side of the axis is equal to the increased volume ofliquid on the other side of the axis in all positions of the carburetor,when tilted through a relatively large angle.

The forms of my invention herein illustrated and described representtypical embodiments of carburetors that may be made to embody thefeatures of my invention. However, it should be understood that numerouschanges may be made in the form, size, and arrangement of the partsemployed Without departing from the spirit and scope of my invention.

What I claim is:

1. In combination with an outboard. motor tiltable about a horizontalaxis to either of two extreme positions, a carburetor movable with saidmotor having a float chamber the inner walls of which are in the form ofa 'gure of revolution about an axis parallel to that about which saidmotor is movable throughout that portion of the chamber. with which theliquid contact changes when the motor is moved from one extreme posi-'tion to another, a float within said chamber controlling the passage ofliquid thereto having the walls thereof above and below the normalliquid level maintained in the chamberl spaced substantially uniformlyfrom the walls of the chamber, and means restricting movement of thefloat within the chamber to a plane substantially bisecting the anglebetween the plane assumed by the surface of the liquid in said chamber'in each of the extreme positions of the motor and the carburetor. v

2. In an outboard motor adapted to be tilted about a horizontal axis fora normal operating position toa tilted non-operating position, andhaving a carburetor carried thereby and movable therewith, andcomprising a float chamber and a liquidfuel inlet valve controllingfloat therein, said float chamber being formed with an opening near itstop located rearwardlyof the center of the chamber and float, and saidfloat chamber and float being so constructed and formed that` thesurface of the liquid fuel remains below said opening when saidoutboardmotor is tilted to the non-operating position.

3. An outboard motor adapted to be tilted about a horizontal axis from anormal operating position to a tilted non-operating position, said motorhaving a carburetor carried thereby and movable therewith, andcomprising a float chamber and a liquid fuel inlet valve controllingfloat therein, said float chamber. being formed with an opening near itstop, and said float chamber and float being so constructed and formedthat the surface of the liquidv fuel remains below said opening whensaid outboard motor is tilted to the non-operating position, saidopening being so located that it is directly above the Iloat when themotor is midway between its extreme positions.

4. An outboard motor adapted to be tilted about a horizontal axis from anormal operating position to a tilted non-operating position having acarburetor carried by the motor and movable positions, and having acarburetor carried by the motor and movable therewith; said carburetorhaving a oat chamber and a oat therein, said float chamber being formedwith an opening near its top of a size suicient to permit insertion andremoval of said iioat, said opening being positioned directly above thecenter of the oat when said motor is midway between said extremepositions.

- 6. In a carburetor, in combination, a substantially cylindrical floatchamber, a. cylindrical oat therein, and means for confining themovement o1 said float to a single plane including bracket

